'72 399 panther bogs out

[98prosport]

I am looking for some tech advise, maybe from someone with experience of owning one of these older sleds.2 cyl fan cooled motor. seems to start and run great at first, for a few miles,then it starts to bog down, sometimes even stalling. but, it will restart. Water in gas? bad ignition? It runs very well "when it runs". Any ideas?

[northwoodsman]

98 i might be wrong it does sound like water
in with the gas. if the ignition is bad replace it hope that helps. or call or local
arctic dealer

[Surface Tension]

Let the gas settle for a day then siphon some off the bottom of the tank and look for water.

I'll guess and say your starving for gas. Either a plugged filter, cracked or loose gas line, or weak pump.
Theres also a pickup line in the tank with a screen on the end. One or both of those could be bad.

[federline]

I just cured this (and hard starting) on my 75 Lynx this winter. It starts first pull now.

I took the tank off and cleaned it with carb cleaner, rinsed with pure gas. I replaced the pickup tube and in-tank intake screen, as well as fuel tubing and inline fuel filter.

I removed, disassembled, cleaned and rebuilt the diaphram fuel pump and carburator. Replaced spark plugs. Re-adjusted idle stop, air screw and throttle slack.

It's reborn now!